Is it Anemia or Junk food?

I noticed a stronger yellowness of my complexion and more potent fatigue for about a month. However, at the same time my eating habits have been terrible, and so have my sleeping habits. I drink maybe two cups of water daily. I can't really stop eating sugar, chips, and candy. I seldom exercise. As of late, I have been going to bed at around one in the morning and then waking up at eleven in the morning. I usually feel kind of groggy and well, kind of gross. I wonder is my sallow skin and sleepiness can be blamed on anemia, or on how I take care of myself? If I took better care of my body would my skin look more radiant and would I feel better, or regardless is it anemia?